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/*-
* Copyright (c) 2003-2007 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "archive_platform.h"
__FBSDID("$FreeBSD: head/lib/libarchive/archive_read_open_fd.c 201103 2009-12-28 03:13:49Z kientzle $");
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_IO_H
#include <io.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "archive.h"
struct read_fd_data {
int fd;
size_t block_size;
char use_lseek;
void *buffer;
};
static int file_close(struct archive *, void *);
static ssize_t file_read(struct archive *, void *, const void **buff);
static int64_t file_skip(struct archive *, void *, int64_t request);
int
archive_read_open_fd(struct archive *a, int fd, size_t block_size)
{
struct stat st;
struct read_fd_data *mine;
void *b;
archive_clear_error(a);
if (fstat(fd, &st) != 0) {
archive_set_error(a, errno, "Can't stat fd %d", fd);
return (ARCHIVE_FATAL);
}
mine = (struct read_fd_data *)calloc(1, sizeof(*mine));
b = malloc(block_size);
if (mine == NULL || b == NULL) {
archive_set_error(a, ENOMEM, "No memory");
free(mine);
free(b);
return (ARCHIVE_FATAL);
}
mine->block_size = block_size;
mine->buffer = b;
mine->fd = fd;
/*
* Skip support is a performance optimization for anything
* that supports lseek(). On FreeBSD, only regular files and
* raw disk devices support lseek() and there's no portable
* way to determine if a device is a raw disk device, so we
* only enable this optimization for regular files.
*/
if (S_ISREG(st.st_mode)) {
archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
mine->use_lseek = 1;
}
#if defined(__CYGWIN__) || defined(_WIN32)
setmode(mine->fd, O_BINARY);
#endif
archive_read_set_read_callback(a, file_read);
archive_read_set_skip_callback(a, file_skip);
archive_read_set_close_callback(a, file_close);
archive_read_set_callback_data(a, mine);
return (archive_read_open1(a));
}
static ssize_t
file_read(struct archive *a, void *client_data, const void **buff)
{
struct read_fd_data *mine = (struct read_fd_data *)client_data;
ssize_t bytes_read;
*buff = mine->buffer;
for (;;) {
bytes_read = read(mine->fd, mine->buffer, mine->block_size);
if (bytes_read < 0) {
if (errno == EINTR)
continue;
archive_set_error(a, errno, "Error reading fd %d", mine->fd);
}
return (bytes_read);
}
}
static int64_t
file_skip(struct archive *a, void *client_data, int64_t request)
{
struct read_fd_data *mine = (struct read_fd_data *)client_data;
int64_t skip = request;
int64_t old_offset, new_offset;
int skip_bits = sizeof(skip) * 8 - 1; /* off_t is a signed type. */
if (!mine->use_lseek)
return (0);
/* Reduce a request that would overflow the 'skip' variable. */
if (sizeof(request) > sizeof(skip)) {
int64_t max_skip =
(((int64_t)1 << (skip_bits - 1)) - 1) * 2 + 1;
if (request > max_skip)
skip = max_skip;
}
/* Reduce request to the next smallest multiple of block_size */
request = (request / mine->block_size) * mine->block_size;
if (request == 0)
return (0);
if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) >= 0) &&
((new_offset = lseek(mine->fd, skip, SEEK_CUR)) >= 0))
return (new_offset - old_offset);
/* If seek failed once, it will probably fail again. */
mine->use_lseek = 0;
/* Let libarchive recover with read+discard. */
if (errno == ESPIPE)
return (0);
/*
* There's been an error other than ESPIPE. This is most
* likely caused by a programmer error (too large request)
* or a corrupted archive file.
*/
archive_set_error(a, errno, "Error seeking");
return (-1);
}
static int
file_close(struct archive *a, void *client_data)
{
struct read_fd_data *mine = (struct read_fd_data *)client_data;
(void)a; /* UNUSED */
free(mine->buffer);
free(mine);
return (ARCHIVE_OK);
}
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